This invention relates to a flexible center connection for use in an occlusion device, and more specifically to a center connection having a flexible section formed of interlocking segments. The flexible section gives the center connection improved torque and flexure characteristics.
Catheters, catheter guide wires, and flexible delivery devices have been used for several years to reach and provide treatment at target locations within the human body. For example, occlusion devices that seal heart defects are delivered to the treatment site via catheter, and balloon angioplasty is performed via catheter. Many designs for catheters and guide wires exist. The most important features of a catheter, guide wire, or delivery device are flexibility, so that it can navigate the winding human vasculature, and torque, so a physician can exert force sufficient to steer the device. Most catheters are made of flexible plastic tubing and come in a variety of lengths and diameters. Most guide wires consist of a metal outer tube comprised of a metal coil coupled with an inner wire.
In practice, physicians generally use a guide wire to reach the desired location in the body. Upon insertion, the guide wire is tracked with either X-ray technology or ultrasound as the physician maneuvers it to the target location within the patient's body. A catheter can then be advanced over the guide wire after the guide wire has reached the treatment site. The guide wire may be left in place or removed while treatment is accomplished via the catheter.
When the physician navigates to the treatment site, the guide wire must have sufficient flexibility to accomplish the sharp and numerous turns in the body's vasculature. If, however, the guide wire is too flexible, the resistance caused by surface contact with the body's vasculature and the numerous sharp turns will cause the guide wire to buckle and the physician will be unable to reach the treatment site. If the guide wire is too stiff, it will not be able to withstand the demanding angles of the vasculature and likewise will not be able to reach the treatment site. Thus there is a need in the art for a delivery tool that possesses both flexibility and navigability.
In addition to the need for delivery tools that possess both flexibility and navigability, other medical devices may be required to be flexible and able to be moved through small diameter catheters. For instance, occlusion devices may be used to repair a wide range of cardiac defects, including patent foramen ovale, patent ductus arteriosus, atrial septal defects, ventricular septal defects, and may occlude other cardiac and non-cardiac apertures. There are currently several types of occlusion devices capable of being inserted via a catheter. The occlusion devices, like the guide wires or catheters, must have sufficient flexibility to accomplish the sharp and numerous turns in the body's vasculature.
Another challenge in deploying an occlusion device in the heart is the variety of the contours of the aperture the occlusion device is meant to close. In particular, when occluding septal defects, the uneven topography in the vascular and septal walls of the human heart makes it difficult to design a device that can adapt to such variations. The challenge in designing an occluder which conforms to the uneven topography is compounded by the fact that the contours of each defect in each individual patient are unique. Poor conformation to the defect results in poor seating of the occlusion device across the aperture, which decreases the ability of the device to successfully occlude the aperture.
Lack of conformation to the walls of the heart can place significant amounts of stress on the occlusion device and decrease the useful life of the device. Once deployed, different parts of the occluder may experience more or less stress as a result of the uneven topography. Having any portion of the occlusion device under increased stress is undesireable.
Thus, there is a need in the art for an occlusion device that will occlude cardiac defects and will match the contours of the heart thereby increasing the life of the device and sealing ability while reducing damage to the surrounding tissue.